diff --git a/server/gameserver/glmhelper.cc b/server/gameserver/glmhelper.cc
index 53c10d8f..783d72e1 100644
--- a/server/gameserver/glmhelper.cc
+++ b/server/gameserver/glmhelper.cc
@@ -90,3 +90,8 @@ bool GlmHelper::IsEqual3D(const glm::vec3& v1, const glm::vec3& v2)
            std::abs(v1.y - v2.y) < 0.00001f &&
            std::abs(v1.z - v2.z) < 0.00001f;
 }
+
+glm::vec3 GlmHelper::Vec2ToVec3(const glm::vec2& v2)
+{
+    return glm::vec3(v2.x, 0.0f, v2.y);
+}
diff --git a/server/gameserver/glmhelper.h b/server/gameserver/glmhelper.h
index ae05a162..b0deed2e 100644
--- a/server/gameserver/glmhelper.h
+++ b/server/gameserver/glmhelper.h
@@ -20,5 +20,5 @@ class GlmHelper
     static float CalcAngle(const glm::vec3& v1, const glm::vec3& v2);
 
     static void FillVert(const glm::vec3& v, float* vert);
-
+    static glm::vec3 Vec2ToVec3(const glm::vec2& v2);
 };
diff --git a/server/gameserver/new_hero_agent.cc b/server/gameserver/new_hero_agent.cc
index f12b4f24..5130d45b 100644
--- a/server/gameserver/new_hero_agent.cc
+++ b/server/gameserver/new_hero_agent.cc
@@ -249,7 +249,7 @@ bool HeroAgent::HasBuffEffect(int effect_id)
 bool HeroAgent::IsNearGas(float anti_range)
 {
     return Collision::InSquare
-        (owner_->GetPos().ToGlmVec3(),
+        (GlmHelper::Vec2ToVec3(owner_->room->GetGasData().pos_old),
          owner_->GetPos().ToGlmVec3(),
          anti_range);
 }